Novolac/Phenol-Containing Phthalonitrile Blends: Curing Characteristics and Composite Mechanical Properties
Hanqi Zhang1, Bing Wang1, Yanna Wang1
1National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin 150001, China.
Polymers
|January 18, 2020
Summary
Blending novolac resin into phenol-containing phthalonitrile resins enhances curing and reduces brittleness. This modification improves fracture strain and glass transition temperature, creating advanced high-performance materials.
Area of Science:
- Polymer Science
- Materials Science
- Organic Chemistry
Background:
- Phenol-containing phthalonitrile resins offer high-temperature resistance but suffer from incomplete curing and brittleness.
- Addressing these limitations is crucial for expanding their application range.
Purpose of the Study:
- To improve the complete curing and mechanical properties of phenol-containing phthalonitrile resins.
- To investigate the effect of incorporating novolac resin on resin properties.
Main Methods:
- Differential Scanning Calorimetry (DSC) and rheological analysis to monitor curing kinetics.
- Fourier-Transform Infrared (FT-IR) spectroscopy to assess chemical conversion.
- Mechanical testing (fracture strain) and Scanning Electron Microscopy (SEM) for material characterization.
- Dynamic Mechanical Analysis (DMA) to determine thermal properties.
Main Results:
- Novolac addition significantly decreased initial curing temperature and gelation time.
- FT-IR confirmed increased nitrile group conversion, with complete reaction at 10 wt% novolac.
- Fracture strain increased by 122% with 10 wt% novolac due to flexible chain segments.
- Glass transition temperature increased with novolac content and post-curing temperature.
Conclusions:
- Blending novolac resin effectively enhances the curing and mechanical properties of phenol-containing phthalonitrile resins.
- The optimized 10 wt% novolac blend offers a promising solution for overcoming brittleness and achieving complete curing.
- The study demonstrates a viable strategy for developing advanced thermosetting materials with improved performance.
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